Form Design for Swedish Social Security office: Font advice for forms?

I am currently in midst of designing a new form for the social security office of the city of Gothenburg in Sweden for the application of financial benefits. The situation of government related documents in Sweden is rather unique, since there are no centralised designs or house fonts and every county can decide on their own forms.

The form is double-sided A3 sheet, which is folded in the middle and has been designed in constant feedback with both social security workers and benefit seekers. However, I am still looking for a suitable font.

The font needs to be a sans serif which works well in small sizes (8pt for the most part). Apart from the disclaimer at the end, it will not be set in continuous text, but rather in single lines underneath the boxes to fill out. It should have a somewhat accessible nature and needs to include the standard Swedish letters Ö, Ä, Å.

There is a large group of benefit seekers with an immigrant background so there will be a filling out help which is translated into Arabic and possibly Somali. If the fonts has some fitting equivalents in these languages it would be a huge benefit.

Hope any of you might have some knowledge about design of forms or for governments and can help me with this.

All Somali orthography I've seen in Sweden has used Roman type, with the only special character being a prime mark glottal stop. Other languages that you'd generally see translations into include Finnish, Farsi, Spanish, Albanian, Polish, Sorani, Latin-orthography Serbian and perhaps some Cyrillic-alphabet ones, perhaps even Mongolian. So wide character set in both Arabic and Roman (and maybe Cyrillic) is a good policy.

A really bloody-literal-minded government agency might even include Hebrew-alphabetted Yiddish, which after all is one of our five official national minority languages...

edit: Oh, and Thai is a definite, slightly scary prospect. You should probably check out exactly what translations will happen before settling on a font.

edit 2: the national social insurance agency (Försäkringskassan) has all the languages above, including Thai and Russian (but not Mongol or Yiddish), Nothern Sami (hello ŋ!), Dari, Turkish, Kurmanci as well as, to make it even harder, Tigrinja.

@ Birdseeding: Since this form will only be used in the city of Göteborg and is specifically tailored for their needs, the only translations needed are in English, Arabic, and Somali. This is because these are the most common languages needed within this specific area.

Nevertheless, the compatibility with those scripts wasn't in fact my main concern.

I was wondering if any of you knew sans serif fonts that have been used in form design and proven to work well both in legibility and "friendly" character.

FF Meta has been successfully used in forms (don’t know whether all exotic languages are supported).
I like FF Azuro a lot — that is quite recent so not much of a track record.
I use FF Axel in my own (in house) forms.
All of these are quite friendly (and economical in use).

I can only guess that sans serif fonts stand for their perception of what modern and approachable design is and tie in with the rest of the print material they put out.
All my remarks about better legibility of serif type faces in small sizes were simply dismissed.